FUEL PROCESSING TECHNOLOGY
·
2021
·
IF 7.033
Qingpo Peng,Xiuge Zhao,Difan Li,Manyu Chen,Xinjia Wei,Jian Fang,Kai Cui,Yuan Ma,Zhenshan Hou
The heterogeneous heteropolyacid-catalyzed acetalization of glycerol with acetone was investigated under solvent-free conditions. In this work, the calcined Ta/W mixed addenda heteropolyacid catalyst ({H 20 }-355) was employed as a solid acid catalyst and showed much higher activity than these soluble Keggin-type catalysts in the acetalization of glycerol with acetone due to its superacidity ( H 0 = −12.95). Meanwhile, it showed high stability in catalytic recycles and extended for acetalization of glycerol with the other aldehydes and ketones . Based on the catalyst characterization by X-ray diffraction (XRD), scanning electron microscopy (SEM), 31 P NMR spectra, FT-IR spectra, pyridine-absorbed FT-IR, and Hammett acidity functions ( H 0 ) by UV–vis spectroscopy, it was found that the acidic strength of the Ta/W mixed addenda heteropolyacid was highly dependent on the contents of crystalline water that could be tuned by calcination temperature. Notably, the solid superacid catalyst {H 20 }-355 was swollen by acetone, exhibiting an interesting “pseudo-liquid” behavior, which served as a microreactor and facilitated the reaction. Furthermore, after the acetalization reaction of glycerol with furfural (98% yield of acetal) on {H 20 }-355 catalyst, the furan ring of the acetal products can be hydrogenated sequentially into dioxolane or dioxane with Pd/C catalyst under room temperature condition without the need of any isolation procedure.
研究领域:
化学工程
·
催化科学
·
可再生燃料合成
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 6
·2362
·
IF 3.4
Kuntong Song,Yi Li,Ruiqi Zhang,Nan Wang,Junhong Liu,Wenxia Hou,Qing Zhou,Xingmei Lu
Compared with conventional pyrolysis, steam-assisted pyrolysis of polyethylene terephthalate (PET) can effectively eliminate char and upgrade terephthalic acid (TPA). However, during steam-assisted pyrolysis of PET, the degree of cracking still varies greatly, and while some of the product is excessively cracked to gas, the other part is still insufficiently cracked. In addition, these two types of products seriously affect the yield and purity of TPA. To further enhance the TPA, an attempt was made to reduce these impurities simultaneously by synergistic catalysis among the different components of the metal–acid catalyst. Through a series of experiments, Pt@Hzsm-5 was screened as the optimal catalyst. In the catalytic steam-assisted pyrolysis of PET, the optimum reaction temperature decreased to 400 °C, the calculated yield of TPA increased to 98.23 wt%, and the purity increased to 92.2%. The Pt@Hzsm-5 could be recycled three times with no significant decrease in the obtained yield of TPA. The catalytic mechanism of the Pt@Hzsm-5 was investigated through the analysis of the products and isotope tracing experiments. The Pt catalyzed the hydrogen transfer reaction between the water molecules and PET molecules, which inhibited the excessive cracking of TPA by improving the hydrogen transfer efficiency, reduced the generation of gaseous products, and improved the calculated yield of TPA. In contrast, the Hzsm-5 catalyzed the reaction of monovinyl ester cracking to TPA, effectively reducing the impurities in the solid product, increasing the olefin yield, and improving the purity of TPA. This discovery not only clarifies the synergistic catalytic effect of the Pt@Hzsm-5 in the steam-assisted pyrolysis of the PET reaction but also lays the foundation for further screening of other inexpensive metal–acid catalysts. This is of great significance to realize the industrial application of TPA preparation by PET pyrolysis.Keywords:PET;metal–acid catalyst;steam-assisted pyrolysis;TPA
研究领域:
化学工程
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催化材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2021
·
IF 3.605
Hao Xu,Shanshan Xiong,Yuan Zhao,Lingjun Zhu,Shurong Wang
Furfural is an important platform chemical that can be produced by dehydration of pentose, which is an important building block of lignocellulosic biomass. In this study, xylose was chosen as the reaction substrate, and a carbon-based solid acid prepared from pectin was used as the catalyst in a mixed solvent consisting of water and γ-valerolactone (GVL). FTIR results showed that the sulfonated catalyst had typical characteristic peaks of sulfonic groups, while the results based on NH3-TPD and elemental analysis showed that the sulfonation temperature changed the surface acid concentration and acid site intensity of the catalyst. A furfural yield of 80.4% and a xylose conversion of 100% were obtained at 170 °C for 60 min. The conversions and product yields were influenced by the reaction temperature, reaction time, solvent composition, and catalyst acidity. Different sulfonation temperatures can change the acidity of the catalyst, which determines the catalytic performance of the catalyst.
研究领域:
生物化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2018
·
IF 0
Yuying Zhang,Chuang Li,Zhongtian Du,Xiao Chen,Changhai Liang
Transformation of renewable biomass into chemicals has attracted much attention recently. Efficient catalytic dehydration of biomass-derived sorbitol into isosorbide over solid acid catalysts under moderate reaction conditions is still a technical challenge. A series of silver-exchanged phosphotungstic acid catalysts were prepared by an ion-exchanged process, and dehydration of sorbitol into isosorbide was performed under solvent-free conditions. More than 99% conversion of sorbitol was obtained with 83% selectivity of isosorbide over Ag 1 H 2 PW catalyst at 140 °C within 1 h, which are comparable with that using a homogeneous phosphotungstic acid (HPW) catalyst. The silver-exchanged phosphotungstic acid catalysts were characterized by various techniques such as XRD, FT-IR, Raman, NH 3 -TPD and Py-IR to build a relationship between the catalytic activity and their natures. Ag 1 H 2 PW exhibited much higher activity for catalytic dehydration of sorbitol to isosorbide compared with Ag 2 H 1 PW and Ag 3 PW under the same reaction conditions, which was attributed to the stronger acidity and higher amount of Brönsted acid sites. Moreover, Ag 1 H 2 PW could be easily regenerated by 65% HNO 3 solutions and used repeatedly at least 3 times without obvious loss of catalytic activity.
研究领域:
化学工程
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催化
·
可再生能源
✓ 已验证
产品关联
DOI
ChemistrySelect
·
2024
·Vol. 9
·期 40
·e202402030
·
IF 1.9
Wei Tang,Haojie Qian,Xinyue Wang,Caoxing Huang
Graphical The solid acid catalysts were triumphantly prepared using the residues of poplar sawdust's enzymatic hydrolysis, which displayed the most acidic sites and high catalytic activity, and achieved the highest furfural yield and furfural selectivity during xylose conversion. The utilization of biomass as a carbon source for the synthesis of renewable solid acid catalysts (SA) has emerged as a prominent research direction in the field of heterogeneous catalysis. Based on the challenges associated with reusing residues from lignocellulosic biorefining, the biomass-based SA (BCSA) were prepared using poplar sawdust (PS), hydrothermally pretreated PS (PPS), and the residue of PPS's enzymatic hydrolysis (ER). The characterization revealed that all three types of BCSA were loaded with catalytic groups, and the BCSA synthesized using ER rich in lignin components exhibited a highly efficient catalytic structure. Furthermore, the catalysis of a 20 g/L xylose solution with BCSA-ER as SA also achieved the highest furfural yield (89.3%) and furfural selectivity (90.3%). The findings of this study suggested that lignin holds significant potential as a carbon carrier for SA, thereby offering a viable solution for utilizing by-products from lignocellulosic biorefining.
研究领域:
生物化学
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催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2014
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IF 5.039
Huiling Li,Aojie Deng,Junli Ren,Changyu Liu,Qi Lu,Linjie Zhong,Feng Peng,Runcang Sun
Selectively catalytic hydrothermal pretreatment of corncob into xylose and furfural has been developed in this work using solid acid catalyst ( SO 4 2 - /TiO 2 –ZrO 2 /La 3+ ). The effects of corncob-to-water ratio, reaction temperature and residence time on the performance of catalytic hydrothermal pretreatment were investigated. Results showed that the solid residues contained mainly lignin and cellulose, which was indicative of the efficient removal of hemicelluloses from corncob by hydrothermal method. The prepared catalyst with high thermal stability and strong acid sites originated from the acid functional groups was confirmed to contribute to the hydrolysis of polysaccharides into monosaccharides followed by dehydration into furfural. Highest furfural yield (6.18 g/100 g) could be obtained at 180 °C for 120 min with 6.80 g/100 g xylose yield when the corncob/water ratio of was 10:100. Therefore, selectively catalytic hydrothermal pretreatment of lignocellulosic biomass into important platform chemicals by solid acids is considered to be a potential treatment for biodiesel and chemical production.
研究领域:
生物化学
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可再生资源与环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Weitao Wang,Xiaomei Cao,Haishun Guo,Xiufang Yang,Nianwen Guo,Yangmin Ma
The carbon-based solid acid catalyst was prepared by carbonizing lignin and polyvinyl chloride at high temperature and then sulfonating with p-aminobenzenesulfonic acid. The catalyst was characterized by FI-IR, XPS, SEM, N 2 adsorption-desorption, and acid-base titration to reveal the physical and chemical properties of the catalyst. In addition, the effects of reaction temperature, time, catalyst loading, and solvent type on transformation of xylose to furfural were also investigated. The yield of furfural can reach 84.3% from xylose in GVL solvent. In addition, five common crop wastes of corn cob, corn stalk, rice straw, rice husk, and wheat straw are employed as the substrates over the as-prepared solid acid to investigate the catalytic performance. Satisfied yield of furfural from corn cob and rice husk are achieved. The results show that the prepared solid acid has good catalytic performance for the reaction of furfural production from biomass.
研究领域:
化学工程
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生物质能
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
BIOMASS & BIOENERGY
·
2023
·
IF 6
Lihe Zhu,Xueting Shao,Xuejun Pan,Zhong Sun,Xiangyu Li,Xixin Duan,Junyou Shi
Catalytic conversion of waste biomass to furfural (FF) is an important valorization of lignocellulose . Heteropolyacid catalysts were designed for efficient aqueous-phase dehydration of saccharides by supporting phosphotungstic acid (H 3 PW 12 O 40 , abbreviated as PW 12 ) on H-ZSM-5 zeolite at different loadings (xPW 12 /ZSM-5, x = 10%, 20%, 30%, 40%, 50%). The PW 12 /ZSM-5 was used in the one-pot conversion of biomass (xylose, xylan , and corn stover) to FF in LiBr aqueous solution. The low PW 12 loading catalyst (10%PW 12 /ZSM-5) could efficiently convert biomass to FF with the yields of 73.3% (xylose) and 75.1% (xylan) at moderate temperature (130 °C), respectively. The PW 12 loading and acid sites distribution were crucial to the catalytic performance. Moreover, LiBr enhanced the yield of FF because of its Lewis acidity. The PW 12 /ZSM-5 based solid polyacid was a promising catalyst for the efficient FF production from biomass with high yield and easy separation.
研究领域:
生物化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 10
·1327
·
IF 3.9
Di Wang,Jiangang Lv
Methyl glycolate was synthesized as a precursor to ethylene glycol from the acid-catalyzed carbonylation of formaldehyde, followed by esterification with methanol. Homogeneous acids and different solid acids (e.g., resins and zeolites) were used as catalysts, and the effect of the solvent was examined. Afterward, a carboxylic acid protection strategy was proposed. With sulfolane and acetic acid as the mixed solvent, the solubility of CO increases, and the reaction rate can be accelerated. The rapid reaction between acetic acid and glycolic acid inhibits glycolic acid polymerization and pulls the reaction balance to promote the carbonylation reaction rate. Under the optimal solvent system (a molar ratio of acetic acid to sulfolane of 1:5) and the appropriate reaction conditions, the selectivity of the target product is higher than 85%. Solid acid catalysts with a −SO3H or −CF2SO3H functional group are supposed to be efficient in the carbonylation of formaldehyde, based on which a supported Nafion catalyst with a high surface area and total acid content was designed and synthesized. The novel supported Nafion catalyst presents a high total acid content and high Brönsted–Lewis acid ratio due to the characteristics of modified zeolite and, thus, leads to the high reactivity and very low selectivity of the by-product. A possible reaction mechanism is proposed to explain the product’s distribution by ascribing the formation of different products to different types of acid sites.Keywords:carbonylation;formaldehyde;methyl glycolate;ethylene glycol;acid catalyst
研究领域:
化学合成
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED ENERGY
·
2024
·
IF 10.1
Yingjie Niu,Ting Li,Ali Hassan Bhatti,Jiaqi Qu,Xin Zhou,Li Luo,Francesco Barzagli,Chao'en Li,Rui Zhang
The use of solid acid catalysts for sorbent regeneration is an emerging approach to improve the energy efficiency of CO 2 capture processes. In this study, fly ash (FA), an industrial byproduct rich in acid/base sites, was chosen as a support material for the solid acid SO 4 2− /ZrO 2 (SZ) in the preparation of SZ@FA composite catalysts. Three catalysts with different mass ratios between SZ and FA were synthesized and evaluated in the regeneration process at 88 °C of a CO 2 -saturated MEA solution. Their desorption performance, expressed as CO 2 desorption rate, amount of CO 2 desorbed , and heat duty, was then compared with that obtained with unmodified FA, ZrO 2, and in the absence of catalysts (blank), under identical operating conditions. Compared to the uncatalyzed system, the SZ@FA composite catalysts showed significantly better desorption performance. In particular, SZ@FA-1/2 provided the highest values of desorption rate and cyclic capacity while reducing energy consumption by 45.4% compared to the blank system. It also demonstrated stability over 20 consecutive absorption-desorption cycles. Comparison with other reported catalysts highlighted the high performance of SZ@FA-1/2, particularly in terms of relative heat duty reduction, positioning it as a cost-effective and environmentally friendly choice for post-combustion capture applications.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Ruru Zhou,Yuanyuan Jiang,Huaiyuan Zhao,Boyong Ye,Lina Wang,Zhaoyin Hou
Acetalization of glycerol with acetone could convert surplus glycerol into an important fuel additive (solketal). In this work, a stable solid acid catalyst was synthesized in a facile polycondensation of p -phenolsulfonic acid on KH560 modified SiO 2 (PSF/K-SiO 2 ) and used in the acetalization of glycerol at room temperature. Characterization results confirmed that PSF/K-SiO 2 possessed larger surface area and surface acidity than that of PSF resin (copolymer of p -phenolsulfonic acid and formaldehyde) and non-modified SiO 2 supported PSF resin (PSF/SiO 2 ). As a result, PSF/K-SiO 2 was extremely active and stable in the acetalization of glycerol. At 25 °C, the detected conversion of glycerol reached 86.3% with a 97.7% selectivity of solketal at 1.5 h. The best yield of solketal over PSF/K-SiO 2 could reach 93.1 g-solketal/g-cat/h, and PSF/K-SiO 2 could be recycled at least 5 times without obvious decrease in reactivity.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 11
·9140-9150
·
IF 3.201
Jiliang Ma,Xinwen Peng,Linxin Zhong,Runcang Sun
The application of biomass-based carbonaceous solid acids in catalysis is attracting increasing attention in the field of chemistry. In this study, a heterogeneous carbon-based solid acid biocatalyst (CXH-SO3H) with regular spherical structure was synthesized from xylan-type hemicellulose (XH) by a simple two-step method. The catalyst was successfully applied in the synthesis of O- and N-heterocycles with yields of 80–99% and 60–97%, respectively. In view of environment and economy, CXH-SO3H shows the merits of environmental friendliness, easy operation, simple work-up, excellent yields, and the avoidance of use of organic solvents and expensive catalysts. Moreover, the as-synthesized solid acid catalyst could be used for several cycles without significant loss in its catalytic activity. The results of FT-IR, XRD, and SEM showed that no distinct differences in physico-chemical structures of CXH-SO3H were observed. Thus, the eco-friendly CXH-SO3H catalyst is a promising candidate for green synthesis of O- and N-heterocycles from low-cost feed-stocks and has good prospect in partially substituting commercially available solid and liquid acid catalysts and precious metal catalysts.
研究领域:
化学
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可再生资源
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）